Can I make my car stay in open loop?

drodgers
09-09-2003, 12:32 PM
My 95 Z has developed a problem and I'm waiting for a cable from AKM to scann for codes.
It rins fine in open loop but dies as soon as temp comes up to 160 so I'm asuming that's when it goes to closed loop.
If I let it sit till it's cold again same thing happens.
I would like to get it to stay in open loop to see if I can at least get to work and home which is only a couple miles,until I can diagnose what the problem is.

turbo_Z
09-09-2003, 01:18 PM
unplug one of your 2 oxygen sensors and that should do the trick.

drodgers
09-09-2003, 11:11 PM
Tried unplugging them both.Is there a reason to unplug one and leave the other hooked up?

turbo_Z
09-10-2003, 12:00 AM
Originally posted by drodgers
Tried unplugging them both.Is there a reason to unplug one and leave the other hooked up?

1 is all you need to keep the car in open loop.. unplugging both is basically twice work for the same outcome.

drodgers
09-10-2003, 12:09 AM
Well unplugging them didn't make a difference.I guess I will have to wait to see what code it's showing.Can you recommend a good scanning program?
My friend has a laptop and said if I get the cable he'd get a download and scan it.

turbo_Z
09-10-2003, 12:52 AM
http://www.ttspowersystems.com/

download the free trial version of TTS Datamaster. you get something like 20 free logs and infinite reads so that should work for you. hope that helps out! sounds to me like its not an open/closed loop problem.. maybe opti (easy target when it comes to LT1s)

drodgers
09-10-2003, 01:40 AM
tThanks,I don't think it's opti because the car runs great even wide open when cold temp.No hesitation or misfire or backfire.Temp comes up and it dies out like running out of gas or turning of the key.I can pull the fuse and reset the comp.but it will only run for a minute each time.
Let it set till cold and it runs great like nothing was ever wrong till the temp comes up.
I think this rules out fuel or ignition systems and narrows it down to a sensor failure when it starts in closed loop and starts reading sensor information.
Of course I'm old school and these computer systems don't seem to care what I think.

turbo_Z
09-10-2003, 11:53 AM
you know i have heard of ICM or ignition control modules do what you are describing when they get hot. the module is a small black domino looking sensor located on the coil bracket right next to your coil which is on the head. i havent had any experience with one failing on me but what i have read is that when the module starts to near its death, it will fade in and out when it gets really hot. im sure its relatively inexpensive judging by its size.. id still try to get the car scanned first however.

drodgers
09-10-2003, 11:07 PM
Yeah,I don't want to try replacing stuff without scanning it first.I was hoping to find a cheap scanner like they have for ford but the one for this car is $150 and I got the cable for $95 and can use it for tuning also.Shoud be here tomorrow or friday.Hope it's something simple.

Cam94Z28
04-12-2004, 01:02 AM
I wonder if the ICM can cause a random stumbling miss once the car reaches operating temp, which is what mines doing. It's basically the only ignition component thats never been replaced in 130,000 miles. I have ordered a cable from mastach.com though, so i'll test first.

jdizzell
04-12-2004, 06:25 PM
Originally posted by drodgers
tThanks,I don't think it's opti because the car runs great even wide open when cold temp.No hesitation or misfire or backfire.Temp comes up and it dies out like running out of gas or turning of the key.I can pull the fuse and reset the comp.but it will only run for a minute each time.
Let it set till cold and it runs great like nothing was ever wrong till the temp comes up.
I think this rules out fuel or ignition systems and narrows it down to a sensor failure when it starts in closed loop and starts reading sensor information.
Of course I'm old school and these computer systems don't seem to care what I think.

Have you tired hitting WOT when the temp is up? When the opti starts to go, it runs fine when cold, then when the temp is up the opti will start to crap out. It sounds like your opti!
http://web.camaross.com/forums/showthread.php?s=&threadid=232492